1. Field
The present disclosure relates generally to manufacturing objects and, in particular, to a method and apparatus for measuring the thickness of a structure. Still more particularly, the present disclosure relates to a method and apparatus for measuring the thickness of a structure to identify a bolt length.
2. Background
Parts may be fastened to each other using a number of different types of fastener systems. These fastener systems may include, for example, without limitation, rivets, bolts and nuts, and other suitable types of fastener systems. The use of a bolt and a nut provides a capability to fasten parts together to form a structure. Further, with the use of a bolt and a nut, a capability exists to more easily disassemble the structure at a later point in time as compared to other fastener systems, such as rivets.
In some cases, a typical hex nut may be impractical, increase maintenance efforts, and/or increase difficulty in disassembly. In these situations, a nut in the form of a nut plate is often used.
A nut plate also may be used in blind mount applications. For example, the bolt may be screwed into a structure for which the side on which the nut is to be placed is inaccessible. With this type of installation, a nut plate may be secured to the side of the structure that will be inaccessible. The nut plate may be secured using rivets, adhesive, and/or other types of attachment techniques. These nut plates may have fixed or floating nuts and may be covered with a fluid tight housing.
When using a nut plate, a hole is drilled through the structure with a desired diameter to accommodate a bolt. The diameter of the hole may be used to identify the diameter of the threaded hole to select the nut plate. The diameter of the threaded hole in the nut plate is typically approximately equal to or slightly less than the diameter of the hole through the structure. Although the diameter of the hole may be established, the length of the bolt needed to pass through the hole of the structure and become threaded with a desired tightness in the nut plate is not always easy to identify. Further, it is desirable for the threaded end of the bolt to protrude or extend a selected distance beyond the nut plate.
After a nut plate is installed and the structure is in place, a selected bolt is inserted into the hole and engages the nut plate to secure the structure in place and/or together. With this type of fastening system, the bolt may have a shank having a smooth section and a threaded section. It is often desirable to have the threaded section present in the portion of the shank that engages the nut plate. Having a threaded portion that may bear or rub against the structure is undesirable.
Measurements may be made to identify a grip length for the bolt. The grip length is the smooth part of the shank that has no threading. Further, the smooth part of the shank also should not engage the nut. This type of situation may result in an inability to tighten a fastener to the desired amount.
If the measurements are incorrect, the bolt may be removed and replaced with a new bolt having a shank with the correct length for the smooth section and the threaded section.
Therefore, it would be advantageous to have a method and apparatus that takes into account one or more of the issues discussed above, as well as possibly other issues.